About Walter J. Willoughby, Jr., M.D.With board certification in pulmonary medicine, sleep medicine, and internal medicine, Walter J. Willoughby, Jr., MD, is uniquely qualified to provide comprehensive care to women and men living in the Las Vegas area. Patients always feel welcome at his practice, where the staff members know each patient by name and take the time to listen to their concerns.Dr. Willoughby provides personalized and patient-centered care, with a focus on keeping his patients healthy and out of the hospital. Patients can count on receiving the full range of services, including getting their lung function testing done in the office, which is fully equipped with advanced pulmonary testing technology.